Members of the right-wing Swiss People's Party, currently the largest party in the Swiss parliament, have launched a campaign to have the building of minarets banned.

They claim the minaret is not necessary for worship, but is rather a symbol of Islamic law, and as such incompatible with Switzerland's legal system.

Signatures are now being collected to force a nationwide referendum on the issue which, under Switzerland's system of direct democracy, would be binding.

The move has shocked Switzerland's 350,000 Muslims, many of whom have been campaigning for decades for more recognition for their faith.

In theory Switzerland is a secular state, whose constitution guarantees freedom of religious expression to all. In practice however mosques in Switzerland tend to be confined to disused warehouses and factories.

Across the country, there are only two small minarets, one in Zurich and one in Geneva, neither of which are permitted to make the call to prayer. In Switzerland's capital Berne, the largest mosque is in a former underground car park.

Plans rejected

In the small town of Langenthal, just outside Berne, plans to build a very modest minaret have been put on ice following thousands of objections.

Many Swiss think minarets have no place on their urban skylines

Langenthal's mosque is housed in a former paint factory on the outskirts of town.

Mutalip Karaademi, an ethnic Albanian who has lived in Switzerland for 26 years, was at first pleased when his proposal for a 5m-high (16.5ft) minaret was approved by the local authority.

But following a vociferous campaign against the plans, including a petition with thousands of signatures, the cantonal government in Berne delayed the project indefinitely.

"We are very disappointed," said Mr Karaademi. "We just wanted to do our mosque up a bit, with this small minaret and a tea room. We actually thought it might promote dialogue."

Mr Karaademi is also bitter at what he sees as unfair discrimination against his faith. "I even gave them a written undertaking that we would never make the call to prayer," he said. "They seem to think we are all criminals or terrorists - that's like saying all Italians are in the mafia."

Islamic law

But supporters of a ban on minarets say they have no intention of preventing anyone from practising their faith.

"We don't have anything against Muslims," said Oskar Freysinger, member of parliament for the Swiss People's Party.

"But we don't want minarets. The minaret is a symbol of a political and aggressive Islam, it's a symbol of Islamic law. The minute you have minarets in Europe it means Islam will have taken over."

Mr Freysinger's words may sound extreme, even paranoid, but this is a general election year in Switzerland, and the campaign against minarets is playing well with voters.

A recent opinion poll for one Swiss newspaper found that 43% of those surveyed were in favour of a ban on minarets.

"We have our civil laws here," insisted Mr Freysinger. "Banning minarets would send a clear signal that our European laws, our Swiss laws, have to be accepted. And if you want to live here, you must accept them. If you don't, then go back."

Growing resentment

It's a harsh message for Swiss Muslims, many of whom were born in Switzerland. There are fears that the campaign against minarets will provoke growing resentment against Swiss society.

"I think Swiss Muslims will be angry and bitter over this," said Reinhard Schulze, professor of Islamic Studies at Berne University. "And we know that anger and bitterness among a community can lead to radicalisation, even to militancy."

The Swiss government is extremely nervous about the prospect of militancy among Swiss Muslims; three cabinet ministers have already spoken out against the campaign to ban minarets.

There is also a growing fear that the debate will damage Switzerland's traditionally good relations with the Arab world.

But the Swiss People's Party is powerful. If the minaret campaign is, as some suspect, a vote-grabbing ploy ahead of October's general election, then it is a successful one; the party is riding high in the opinion polls.

A constitutional amendment forbidding minarets will have to be approved in a nationwide referendum. In the meantime, no minarets are being built anywhere in Switzerland; the controversy has created a situation in which no local planning officer wants to be the first to approve one.

In that respect, the People's Party may have got what it secretly wanted all along, an unofficial ban on minarets.

So for now, Switzerland's Muslims will continue to pray in abandoned buildings, many with the growing feeling that they are tolerated only as long as they remain invisible.